水温对虹鳟血清无机微量元素含量影响的初步研究

使用日立7170A全自动生化分析仪和贝克曼CX-3电解质分析仪,检测不同水温虹鳟血清中无机微量元素含量.结果表明,水温14～23℃,虹鳟血清中铜元素含量比鳙鱼随水温变化显著,钾、磷、钙、钠、氯元素含量变化不显著.分析了虹鳟在温水环境中血清无机微量元素含量的变化规律.     

水温对虹鳟幼苗血糖值与存活率的研究

设计7个水温(12℃、14℃、16℃、18℃、20℃、22℃、24℃)组,根据虹鳟幼鱼初始体重细分3个体重组(0.6g、1g、2g),共计105尾鱼苗,研究水温对虹鳟幼苗血糖值与存活率。结果表明:虹鳟幼苗血清血糖含量随水温升高而升高,在水温20℃时血糖含量最高,2g组虹鳟幼苗血糖含量最高;当水温处于12℃~20℃时,虹鳟幼苗成活率随着水温升高而升高,而水温达22℃~24℃时,其成活率有所下降,并于20℃、24℃时各有一个转折点。     

不同水温下虹鳟血清酶的活性

使用日立7170A全自动生化分析仪,测定水温14℃、19℃、23℃时虹鳟(Salmo irideus)血清酶活性。结果表明:在3个温度下,虹鳟血清碱性磷酸酶(ALP)和肌酸激酶(CK)活性随温度上升而降低,谷丙转氨酶(ALT)活性随温度上升而升高,谷草转氨酶(AST)活性表现为先升高后降低,乳酸脱氢酶(LDH)活性表现为先降低后升高。     

水温对怀头鲇血液学指标的影响

本实验设定4℃、9℃、14℃、18℃、24℃和30℃6个水温梯度，测定了水温变化对二龄怀头鲇血液生理生化指标的影响。结果显示，水温4～30℃范围内，怀头鲇血红蛋白含量随着水温的升高呈波浪型变化，但变化幅度较小；而血沉与血红蛋白含量变化趋势相反，变化幅度较大；血液中的红细胞数量随水温的升高先增加再减少；血清中的总蛋白、白蛋白和球蛋白的变化趋势一致，都是随水温的升高其含量先增加再减少，而且在9～18℃区间变化较急剧；血清中的血糖，高密度脂蛋白，谷草转氨酶，三碘甲状腺氨酸，甲状腺素，促甲状腺激素，钾和镁八项指标在各水温之间不存在显著差异（P〉0．05）；血清中的尿素氮，甘油三脂，总胆固醇，低密度脂蛋白，谷丙转氨酶，碱性磷酸酶，钠，钙，氯化物和渗透压在部分水温之间存在显著差异（P〈0．05）。     

水温对虹鳟四种血清酶活性影响的比较研究

使用DS-2000全自动化分析仪，测定水温15℃、16．5℃、18．5℃和22℃时虹鳟血清酶活性。结果表明：谷氨酸脱氢酶（GLDH）活性在水温15℃～16．5℃小比率降低，16℃～18．5℃大比率升高，18．5℃～22℃较大比率降低；a-羟丁酸脱氨酶（a-HBDH）活性在水温15℃～16．5℃小比率降低，16，5℃～18．5℃较大比率增加，18．5℃～22℃较大比率降低；脂肪酶（LPS）活性在水温15℃～16．5℃小比率升高，16．5℃～18．5℃小比率降低，18．5℃～22℃小比率升高；淀粉酶（AIMS）活性在水温15℃～16．5℃较小比率降低，16．5℃～22℃小比率升高。本文为揭示虹鳟热致死及耐热机理提供有关数据，为冷水性鱼类虹鳟温水驯化养殖提供基础技术资料。     

突变高温胁迫对大黄鱼血清生理指标的影响

鱼类作为变温动物,在水温突变时体内会发生一系列生理变化。本研究分析了突变高温胁迫下大黄鱼幼鱼血清皮质醇(COR)、血糖(GLU)以及乳酸(BLA)含量的变化规律。实验选取8月龄平均体重为(118.8±6.05)g的大黄鱼作为实验对象,对照组设定温度为(23±0.3)℃,实验组设定温度为(33℃±0.3)℃,变温过程为突变,观察记录实验现象。结果表明:大黄鱼幼鱼在33℃高温胁迫下有强烈的应激反应,表现为呼吸加快、极度不安、游动剧烈。经33℃高温胁迫2 h后,实验组幼鱼血清中皮质醇、血糖、乳酸含量与对照组相比均有显著的升高(P0.05或0.01),陆续出现死亡,最终全部死亡。研究认为,33℃高温胁迫对大黄鱼有致命的影响,在养殖生产过程中要将水温严格控制在33℃以下。     

循环水养殖条件下水温对大菱鲆氨氮排泄、转氨酶及免疫因子的影响

在高密度工业化封闭循环海水养殖条件下（养殖密度为14?2±0?48 kg／m2）,选取大菱鲆（371?68±43?15 g）360尾,随机均分4组,设置4个水温梯度14℃、16℃、18℃和21℃,旨在探寻水温对大菱鲆氨氮排泄、转氨酶及血清免疫因子的影响,试验期为56 d。结果表明：（1）养殖水体总氨氮浓度随水温升高呈先升后降,18℃时总氨氮浓度极显著高于14℃、21℃时;大菱鲆氨氮排泄率随水温升高而升高,且二者呈指数关系。（2）大菱鲆肝脏GPT、GOT活力随水温升高呈先升后降,均在18℃达最大值;而血清两种指标变化趋势与之相反,均在21℃达最大值。（3）血清LZM、SOD活力及皮质醇含量均随水温升高呈先升后降,均在18℃达最大值;血氨含量则逐渐下降,14℃时极显著高于18℃、21℃时;鳃丝Na＋?K＋?ATPase活力随水温升高而升高,但组间差异不显著。综上,封闭循环水养殖大菱鲆的适宜水温为16～18℃。     

虹鳟鱼种耐高温养殖研究

本项目研究根据夏季江苏虹鳟养殖的环境条件(彩中插2),观察其所能忍受的极限水温及摄食情况,发现水温在27℃左右虹鳟仍能生存。其低密度养殖的平均成活率为98.4%,体重平均增长4.15倍;高密度养殖的平均成活率为98.2%,体重平均增长3.99倍。该试验为虹鳟在江苏的养殖提供一定参考依据。     

史氏鲟的生物学特性及其人工繁殖技术

史氏鲟为典型的河道鱼类,栖息于砂砾底质的江底,适温范围广,生存水温为1~30℃,适宜水温14~26℃,最佳水温18~22℃。史氏鲟雌体怀卵量一般为3万~160万粒。雌体怀卵量占体重的10%~42%,平均为25%。孵化水温为16~24℃,最适水温为19~22℃;平均水温17℃时,约105 h出膜;平均水温21.5℃时,约81 h出膜。     

池养日本对虾越冬与交配技术的研究

本文主要对池塘养成的日本对虾越冬与交配技术进行了研究,亲虾放养密度为15尾/m2时,越冬平均成活率最高,为91.9%;放养密度为20尾/m2时,交配率最高,为66.1%;铺沙厚度为2cm、4cm时,亲虾越冬成活较高,分别为95.1%、96.2%;水温在17℃～23℃之间时,亲虾交配率最高为61%。当光照强度为100～500lx时,亲虾交配率最高,为65.1%。从而提出在现有条件下,日本对虾越冬、交配放养密度10尾/m2～20尾/m2,交配亲虾雌雄比1∶1,越冬、池底铺沙2～4cm,越冬水温10℃～14℃,交配水温17℃～23℃,越冬、交配光照强度100～500lx。     

Determining the optimum doses of Kurasan (ethoxiquinolin) and butylhydroxytoluol (BHT) in dry pellets: effect of both anti-oxidants on some haematological and condition parameters of rainbow trout, Salmo gairdneri Richardson

Abstract. Kurasan and BHT were tested at doses of 100, 200 and 400mg kg^-1 incorporated in dry pellets. The administration of these antioxidants did not influence the red blood count of rainbow trout, Salmo gairdneri Richardson, at body weights of 100 to 400g, reared in flow-through tanks at water temperatures of 7 to 13°C and in cage culture at water temperatures of 15 to 2O°C. In laboratory experiments at a water temperature of 14°C, the highest Kurasan dose increased the red blood cell (RBC) count insignificantly by 14% (1.06 vs 0.93 10¹²1^-1) after 80 days, haematocrit (PCV) was increased by 27% (0.410 vs 0.32511^-1), and haemoglobin (Hb) by 16% (72 vs 62gl^-1), This was seen in the cage culture experiment, but not in the experiments in the flow-through tanks. A trend of diminishing haematological parameters of the red blood count and total blood serum protein (TP) of the fish fed with BHT-stabilized diet was recorded only under laboratory conditions at the water temperature 9°C, The decline of RBC count in the experimental group with 0.04% BHT represented 14% (0.90 vs 1.05 10¹²1^-1), the decline in PCV amounted to 18% (0.328 vs 0.39811^-1), Hb to 17% (57 vs 69g 1^-1), and TP to 11% (39 vs 44g 1^-1).     

Blood chemistry and acid-base balance in rainbow trout Oncorhynchus mykiss with experimentally-induced acute bacterial gill disease

Rainbow trout were experimentally infected with the causative agent of bacterial gill disease (BGD) (Flavobacterium branchiophilum) via bath challenge. All fish were cannulated with dorsal aortic catheters, had nasogastric tubes sutured in place for feeding, and were maintained individually, in plexiglass boxes with a flow-through water system. Fish were either fed, or unfed during the trial. Acute changes in blood gas, serum biochemistry and clinical parameters were monitored. By 24h post-challenge, BGD-infected trout that had been fed had significant hypoxemia, hypercapnia, increased blood ammonia, hypoosmolality, hyponatremia, hypochloremia, and increased cough and respiratory rates when compared to control levels. Unfed BGD-infected trout had similar, but less severe blood gas and clinical changes, and no electrolyte disturbances. The BGD-induced hypoxemia is likely exacerbated by increased oxygen demands brought on by feeding. It is not known what association feeding has with the development of low serum ion levels in BGD-infected trout. This is the first study to report the use of fed fish, as opposed to unfed or starved trout, in obtaining blood chemistry values from indisturbed and cannulated animals.     

低聚木糖对斑点叉尾(鲴)生长及血液指标的影响

在平均体质量10.50 g的斑点叉尾(鲴)基础饲料中分别添加0、0.01％、0.05％、0.10％的低聚木糖,26℃饲喂50 d后,检测鱼体生长性能、肌肉营养成分及血液指标.试验结果表明,低聚木糖对血清中血肌酐含量和血液中红细胞数量、血红蛋白含量影响不显著(P＞0.05),但可显著降低血清中甘油三脂、总胆固醇、血糖、尿...     

Habitat selection by rainbow trout Oncorhynchus mykiss in a California stream: implications for the Instream Flow Incremental Methodology

We quantified microhabitat selection of rainbow trout (Oncorhynchus mykiss) at 2 flows (low= 1.13 m³. s^?1 and high =4.95 m³. s^?1) in the Pit River, California. Flows were controlled by an upstream dam and habitat availability was similar during 4 sampling periods at low flow and 2 periods at high flow. A principal components analysis reduced 6 microhabitat variables to 3 new variables that explained 80% of the observed variance. The 3 components loaded heavily on velocity variables, depth variables and substrate. Microhabitat selection generally differed among macrohabitats (i. e., pools, runs, and riffles). Rainbow trout selected different microhabitats at high flow relative to low flow in response to the availability of deeper, faster water. At low flow, depth and velocity selection were positively correlated with seasonal temperature change for adults but not juveniles. Rainbow trout apparently sought shelter in interstitial spaces in the substrate of runs and riffles during the day in early winter. Generally, large rainbow trout were observed in pools, intermediate-sized fish in runs, and small trout in riffles. The largest fish occurred in slow, deep areas of pools, where they moved slowly without orientation to flow and were not observed feeding, whereas small fish generally faced upstream and fed in all habitat types. Foraging forays were directed up in the water column at velocities similar to the mean water column velocities at holding positions. Rainbow trout were the most abundant species in 76% of the population survey stations. Other species that might have influenced microhabitat selection by rainbow trout were uncommon.     

Effect of hydrolytically changed and oxidized fat in dry pellets on the health of rainbow trout, Oncorhynchus mykiss (Richardson)

Abstract. (1+) rainbow trout, Oncorhynchus mykiss (Richardson), were reared by two methods (flow-through tanks at an average water temperature of 9°C; floating cages at a water temperature of 17°C) under different hydrological conditions for 120 days to study the effect of the presence of oxidized and hydrolytically altered fats in dry pellets on the red blood count and on the liver somatic index (LSI) and on the spleen somatic index (SSI). The unfavourable effect of hydrolytical decomposition and oxidization of fat on the blood indices was demonstrated by correlation and regression analyses. A high linear (r = -0.852) and parabolic (I = 0.890) dependence of the peroxide value (PV), the 2-thiobarbituric acid number (TBAn) and acid value (AV) on the red blood cell count (RBCc), haematocrit (PCV) and haemoglobin (Hb) was found on the basis of these analyses. This effect was most marked at a low water temperature when it was diagnostically important to respect seriously the decrease in RBCc to 0.78T/l, in PCV to 0.291/l and in Hb to 52g/l. In the cages the changes in the haemogram manifested themselves only in the fish given heavily oxidized fats in the feed (above 0.50% iodine, i.e. 43 mEq/kg oil): their Hb decreased from 83 to 69g/l and PCV from 0.44 to 0.381/l. Rainbow trout reacted to the presence of oxidized fats in feeds by increasing their LSI (2.31 vs 1.73%) and SSI (0.30 vs 0.23%). It is important for lipoid liver degeneration (LLD) prevention to determine the ALT and AST aminotransferase activitics which increased to an almost 4-fold level in the diseased fish (11.7 and 0.96 μcat/l).     

Inhibition of the attachment of Flavobacterium branchiophilum to the gills of rainbow trout, Oncorhynchus mykiss (Walbaum)

Preliminary experiments are described which aimed to identify compounds that could inhibit the attachment of Flavobacterium branchiophilum strains LAB4a and ATCC 35035 to the gills of rainbow trout. Total inhibition was never achieved, regardless of the compound tested. Formalin-killed or acetone-killed F. branchiophilum cells retained at least some of their adherent nature, relative to untreated (live) cells. Adherence was reduced by 22–33% following immersion of fish in one litre of water containing 0.21 mg of a homologous crude fimbrial extract. When fish were immersed in water containing hyperimmune rainbow trout antiLAB4a serum, a dose-dependent decrease in attachment (a reduction of 15% to 63%) of LAB4a to the gills was observed. Rainbow trout anti-LAB4a serum also reduced the attachment of ATCC 35035 to the gills, but this reduction was not significant. Adherence of LAB4a was not inhibited following exposure of fish to group 1 carbohydrates (arabinose, mannose and xylose), group 2 carbohydrates (dextrose, galactose and lactose), group 3 carbohydrates (galactosamine, glucosamine and fucose) or group 4 carbohydrates (N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, N-acetyl-neuraminic acid and the globoceramide glycolipid from human erythrocytes). In contrast, when rainbow trout erythrocytes were incubated with the bacteria prior to bath challenge, this resulted in an 87% and 53% reduction in gill-associated LAB4a and ATCC 35035 antigen, respectively, following immersion of rainbow trout in this suspension.     

子二代中华鲟对急性低温胁迫的生理响应

为探究急性低温胁迫对子二代中华鲟抗氧化、免疫及消化酶活性的影响,将健康子二代中华鲟[体质量(1.72±0.33) kg]由23 ℃水体中直接转入17、11 ℃水体中,急性胁迫2 h后取样,检测各项指标。试验结果显示,血清抗氧化指标中,超氧化物歧化酶、过氧化氢酶活性随水温骤降温差增大,呈先升后降的趋势;而谷胱甘肽、丙二醛含量则呈先降后升的趋势( P >0.05);总抗氧化能力逐渐升高。肝脏抗氧化指标中,超氧化物歧化酶和过氧化氢酶活性均呈先升后降的趋势;谷胱甘肽含量逐渐下降,而丙二醛含量却显著增加( P <0.05);总抗氧化能力出现波动( P >0.05)。免疫指标中,血清和肝脏溶菌酶活性随水温骤降幅度的增大,均呈先升后降的趋势,而免疫球蛋白M含量递减( P >0.05)。消化酶指标中,胃、肠和肝脏淀粉酶活性随水温骤降温差的增大,均不断下降;胃、肝脏的脂肪酶活性却持续显著增加( P <0.05);胃蛋白酶活性则出现先降后升的趋势( P <0.05)。试验结果表明,急性低温胁迫对子二代中华鲟的抗氧化、免疫和消化酶活性均产生了较大影响,并对其肝脏产生了一定程度的不利影响。因此,在中华鲟的养殖、运输及人工放流过程中,应尽量避免水温骤降造成鱼体损伤。     

皮质醇混饲投喂对黄颡鱼幼鱼生长及外周血细胞的影响

采用皮质醇混饲投喂的试验方法,模拟自然条件下的慢性应激,观察和分析了应激激素皮质醇对黄颡鱼(Pelteobagrus fulvidraco)幼鱼生长和外周血细胞的效应。试验组饲料中皮质醇添加剂量为100 mg/kg,日投饵率为3%,试验期5周。结果表明:(1)外源皮质醇通过减少肠道黏膜皱褶和促进糖异生作用使黄颡鱼幼鱼增重受阻;(2)外源皮质醇使黄颡鱼幼鱼外周血白细胞数量显著减少、淋巴细胞百分比显著降低,但是中性粒细胞和单核细胞百分比则呈上升趋势;(3)外源皮质醇能促进红细胞增生,增加黄颡鱼幼鱼外周血红细胞数量。     

二倍体与三倍体虹鳟(Oncorhynchus mykiss)红细胞及部分血液指标的比较

对三倍体和二倍体虹鳟(Oncorhynchus mykiss)的红细胞大小(长、短径值和体积)、形态及部分血液指标(红细胞数、血红蛋白、红细胞压积、红细胞脆性和白细胞数)进行了比较。结果表明:三倍体虹鳟红细胞体积与二倍体比值为1.51∶1,细胞核大小与二倍体比值为1.49∶1,与理论值(1.5∶1)比较均无显著差异(P>0.05)。二倍体红细胞短径/长径比值为0.63,呈现出椭圆形;三倍体红细胞短径/长径比值为0.60,呈现出明显的长椭圆形,并有19%的红细胞有哑铃形或分裂的细胞核,这可作为区别二倍体鱼类的一个重要鉴定标志。三倍体虹鳟的红细胞数、红细胞压积和红细胞脆性明显小于二倍体(P<0.05),而血红蛋白与白细胞数与二倍体比较无明显差异(P>0.05)。